Breast Biopsy Needle Type Selection Based On Pathological Diagnostic Needles

https://www.mayoclinic.org/tests-procedures/breast-biopsy/about/pac-20384812

The ultimate goal of a biopsy is to provide a suitable specimen for pathological diagnosis. Therefore, understanding the needs of the pathology department is key to optimizing the selection of breast biopsy needle types. Different types of pathological examinations have drastically different requirements regarding the morphology, quantity, and integrity of the specimen.

Cytological diagnosis primarily relies on fine-needle aspiration biopsy (FNA). This type of breast biopsy needle (21–25G) obtains a suspension of free cells. Its advantages are speed and low cost, making it suitable for large-scale screening and initial triage. However, cytological specimens lack histological information, making it difficult to distinguish between carcinoma in situ and invasive carcinoma, and also unable to accurately assess tumor grade. Therefore, FNA needles are mostly used for cystic lesions or as a rapid preoperative assessment tool, rather than a definitive diagnostic basis.

Histological diagnosis is currently the mainstream goal of breast biopsy, primarily relying on core needle biopsy (CNB) and vacuum-assisted biopsy (VAB). These two types of breast biopsy needles (primarily 14–16G) obtain strip or columnar tissue, preserving the complete tissue structure. This is crucial for determining tumor type (e.g., ductal carcinoma vs. lobular carcinoma), degree of invasion, and vascular invasion. VAB needles, in particular, offer significant advantages in histological diagnosis due to their large sample volume and intact specimens, and can even serve as an alternative to breast-conserving surgery (e.g., VABEx).

The explosive growth in demand for molecular testing has further raised the requirements for breast biopsy needle types. Modern breast cancer diagnosis and treatment has entered the era of precision medicine; ER/PR/HER2 testing and Oncotype DX gene sequencing both require sufficient and high-quality tissue DNA/RNA. This necessitates biopsy needles that can provide a sufficiently large tissue volume (usually several core tissue strips) while minimizing tissue compression and thermal damage. Vacuum-assisted biopsy needles and some large-diameter core needles have therefore become the preferred choice. Furthermore, some special needle types are designed with anti-twist grooves or low-trauma tips to protect nucleic acid integrity.

Immunohistochemical testing is sensitive to specimen fixation conditions. Some breast biopsy needle types are beginning to integrate immediate fixation functions, such as pre-filling the needle with fixative or spraying fixative immediately after sampling to prevent tissue autolysis and ensure no loss of antigenic epitopes.

From a pathology perspective, an ideal breast biopsy needle type should possess the following characteristics: sufficient specimen volume, intact tissue structure, no compression artifacts, no bone tissue contamination (avoiding confusion with calcifications), and timely fixation. Clinicians should proactively communicate with the pathology department when selecting a needle type to understand their testing capabilities and specimen requirements. For example, if the hospital routinely performs multi-gene panel testing, VAB needle types that can provide large samples should be prioritized.

In the future, with the development of liquid biopsy technology, the status of traditional tissue biopsy may be challenged. However, in the foreseeable future, high-quality breast tissue specimens will remain the gold standard. Therefore, optimizing breast biopsy needle types to meet the needs of pathological diagnosis will remain a core direction for product development and clinical application.